Encryption Bug Shedding Light On How U.S. Handles Software Holes And Vulnerabilities

The turmoil caused by the "Heartbleed" encryption bug is shedding light on a little-known element of the White House's surveillance overhaul package: how the government handles software holes and vulnerabilities.

The National Security Agency has compiled a list of software bugs and holes known as "zero days," which the agency has exploited to gain access to secure networks before they can be fixed.